This invention relates to fiber wound composite pressure vessels with integrally formed dual chambers, and a method of fabricating same.
Composite (fiber reinforced resin matrix) containers or vessels have come into common use for storage of a variety of fluids under pressure, including storage of oxygen, natural gas, nitrogen, rocket fuel, propane, etc. Such composite construction provides numerous advantages such as lightness in weight and resistance to corrosion, fatigue and catastrophic failure. This combination of lightness in weight and resistance to failure is possible due to the high specific strength of the reinforcing fibers or filaments (carbon, glass, aramide, etc.) which, in the construction of pressure vessels, is typically oriented in the direction of the principal forces.
One prospective use of composite vessels is as air brake reservoirs for railroad freight cars. Such freight cars currently use cast iron or steel two-chamber pressure containers, but these containers are quite heavy, and difficult to install and maintain. Also, iron and steel corrode so that currently used containers must be coated on the inside to prevent corrosion (caused by condensation in the air pressure system) and this, of course, further increases the cost. Of course, if a way could be found to utilize composite vessels for such air brake reservoirs, then the problems of the heavy weight and corrosiveness would be solved.
Because railroad freight car air brake reservoirs must contain two chambers, and must also be able to withstand high internal pressures, the most obvious approach to utilizing composite vessels for the air brake reservoirs would simply be to utilize a pair of cylindrical composite tanks having domed end sections, with the tanks being joined end to end. However, this arrangement would result in unused dead space between the two tanks which would simply take up space if installed for use in a railroad freight car.